Investigate Geometry and Surface Texture of Selective Laser Melting Built Internal Channels with Varying Inclination Angles using XCT

Additive manufacturing (AM) can produce complex geometries, which is difficult to achieve with traditional processing methods. Selective laser melting (SLM), a commonly used technique in the metal AM industry, performs layer-by-layer fabrication by melting metal powders using one or multiple focused laser beams. Due to the unique manufacturing process, surfaces with different tilt angles are affected by staircase effects and incompletely melted particles, resulting in poor surface quality. The rough surface texture of AM is reported to benefit applications in cooling channels due to increased surface area. Nonetheless, dimensional variation of the cylindrical channel at different inclination angles. For example, the diameter of the vertically constructed channel is closer to the nominal value, and its surface quality is much better. In contrast, the horizontally built channel is affected by the dross formation, has a smaller diameter and is slightly congested.